Point/Counterpoint: Endo first for the treatment of infrainguinal PAD?
We know that the quality of the vein is the critical technical determinant of success, and arterial anatomy is less influential as long as there is outflow to the foot.12 We know that poor quality veins, prosthetics, and other alternatives are much inferior in CLI. And we know that there is a subset of CLI patients who are at high risk for adverse surgical outcomes.13, 14 However one defines them, up to 10% of patients in the large surgical series are in a high-risk group and may not experience meaningful benefit. For endovascular treatments, the data are less clear but certain trends have been consistent. Multilevel disease, long-segment occlusions, heavily calcified lesions, and more advanced tissue loss are negative predictors of clinical success.
Thus at first glance the weaknesses of the two strategies are largely complementary.15 When I encounter an average-risk CLI patient, with an adequate saphenous vein and more than one unfavorable endo factor, I am inclined towards bypass first.
Conversely, endo-favorable anatomy in higher risk patients is a no-brainer. Lots of people fall in the middle, and a significant minority should be considered for primary amputation. Currently my practice is roughly 50% bypass surgery-first in CLI.
Endovascular innovations have made a huge impact on vascular practice, and the leadership of many vascular surgeons (e.g., my esteemed counterpoint author) has been central to advancing the field. Better wires and catheters, retrograde approaches, and drug-eluting technologies continue to be developed at a dizzying pace.
We are all continually learning. Unfortunately, we lack good objective evidence to support most of the expanding armamentarium for CLI. However it is abundantly clear that technical (angiographic) success and clinical success are far apart, which is no surprise. What is surprising is an unsettlingly common lack of honesty about such an obvious fact. Are we all guilty of looking through rose-colored glasses?
Is it really such big news that patency actually matters for most patients with CLI? Technologies will not improve quickly enough if there is no market imperative to make them better. If we continue to buy and use things that are frequently ineffective, or don’t measure it carefully, where is the motivation?
No matter the lens through which one looks at the CLI field, it is desperate for improvement. We need much better technologies that provide longer lasting solutions for patients. We need better diagnostics to predict disease progression and responses to treatment.
We need some new medical or biological therapies that truly alleviate suffering. And we largely lack data on comparative effectiveness, and value, to support thoughtful application of our current treatment arsenal.
Most importantly what we need now is less dogma, and a lot more science. Over more than two decades, multiple RCTs comparing medical, interventional and surgical therapies for coronary artery disease have formed the basis for practice guidelines.
By comparison, our field is nearly incoherent both to vascular specialists and referring physicians. It will not be easy, but this can be done in PAD as well, and the vascular community must embrace it. Moreover it is imperative that vascular surgeons help to lead these multidisciplinary efforts, and develop evidence-based global guidelines to guide best practice in CLI.16 The recent funding of the BEST-CLI trial in the United States and the BASIL-2 trial in the United Kingdom demonstrate the importance to public health and offer great opportunities.
Until better evidence is available, a rational approach to limb salvage requires flexibility, understanding of the factors predicting success/failure for each modality, and the continued use of open bypass surgery as the initial treatment option for a significant number of patients.
And for the sake of our most vulnerable patients, we better keep training vascular surgeons to do all of it well.
Dr. Conte is professor and chief, division of vascular & endovascular surgery and the Edwin J. Wylie, M.D. Chair in Vascular Surgery at the University of California, San Francisco.
References
2. J. Vasc. Surg. 2014;59:220-34
7. J. Vasc. Surg. 2010;51:5S-17S
8. J. Vasc. Surg. 2010;51:18S-31S
9. J. Vasc. Surg. 2011;54:730-6
10. J. Amer. Heart Assoc. 2013;2:e000345
11. J. Vasc. Surg. 2006;43:742-51
12. J. Vasc. Surg. 2007;46:1180-90
13. J. Vasc. Surg. 2009;50:769-75
14. J. Vasc. Surg. 2010;52:1218-25
15. J. Vasc. Surg. 2013;57:8S-13S16. J. Vasc. Surg. 2014;59:510
